Patients are assessed for minimal-residual disease (MRD) status after induction phase. Patients not in remission on day 29 are treated off study. Patients with LR disease are further stratified to LR-reduced (LR-R), LR-standard (LR-S), and LR-intensified (LR-I) groups; patients with HR disease are further stratified to HR-reduced (HR-R), HR-standard (HR-S), and HR-intensified (HR-I) groups. Patients in the LR-R and HR-R groups do not undergo randomization during study.